According to an in-vitro-model of the early allergic reaction in human precision-cut lung slices with passive specific sensitization against grass-pollen, it has been shown that the early allergic response can only be suppressed partly by giving Antihistamines, Leukotriene receptor antagonists or Thromboxane receptor antagonist all on its own. It goes in consent with clinical findings, that all of these drugs alone have just an insufficient activity on asthma.